Lionfish are non-native to the Atlantic, but since 1992, they've quickly been making themselves at home to the despair of native fish, ecosystems, and divers. Now they've reached the Florida Keys, completing a circle that could lead to a major ecological disaster. A 4-inch long lionfish juvenile male was discovered in the Florida Keys, confirming an expected arrival of the non-native species. Lionfish first appeared in the Atlantic not too long ago, in 1992 after Hurricane Andrew swept away a home aquarium containing lionfish. Now, they've spread and are becoming a real issue.

It is believed that lionfish hitched a ride north on the Gulf Stream, up the East Coast, as far as Rhode Island. Other currents and eddies led the lionfish to Bermuda, then to the Bahamas and farther south to the Caribbean as well as Belize. The lionfish was ''completing a loop'' by reaching the Keys, said Lad Akins, REEF's director of special projects.

The problem with lionfish is they eat - a lot. And they don't discriminate when it comes to meals. That means they're eating up native fish that play important roles in balancing the ecosystems in the Atlantic.

In a 2008 University of Oregon State study, the first to quantify the severity of the situation, research teams observed one lionfish gorging on 20 small fish in less than 30 minutes.

Scientists fear the lionfish will kill off helpful species, such as algae-eating parrotfish, allowing seaweed to overtake reefs.

The severity of the situation doesn't escape researchers, who feel this "may well become the most devastating marine invasion in history," nor government officials who worry about safety and the impact on diving tourism (lionfish stings hurt a lot). Officials have asked the public to report any lionfish sightings to the REEF office at 305-852-0030.